Astronomers use many methods to determine this number, including gravitational lensing, the universe’s expansion rate, and more.

The Cassini mission, launched October 15, 1997, concluded on September 15, 2017, after more than 7,000 days of operation. Cassini's observations yielded significant discoveries, including liquid ...

Mars and Spica will appear in close proximity (2° separation) in the evening western sky shortly after sunset, setting before 9 PM local daylight time. Observations of Mars and Spica are best ...

Luna 2, launched by the Soviet Union in September 1959, achieved the first human-made object impact on a celestial body other than Earth (the Moon). The mission's journey to the Moon lasted ...

The International Sun-Earth Explorer-3 (ISEE-3) mission, a joint NASA-ESA endeavor launched in 1978, initially studied the solar wind and Earth's magnetic field from the L1 Lagrange point. Following ...

Yevgeny Khrunov, born September 10, 1933, was selected as one of the first Soviet cosmonauts in February 1960. He participated in the Soyuz 4/Soyuz 5 mission in January 1969, which involved the first ...

Amateur astronomers hold differing views on the significance of observing awards, with some actively pursuing them while others show little interest. The Herschel 400 observing program is frequently ...

Venus, currently traversing Leo, rises around 4:00 A.M. local daylight time (LDT) at 40° N 90° W, preceding sunrise at 6:36 A.M. LDT. By 5:30 A.M. LDT, Venus reaches 15° altitude in the east, with ...

A 250-day experiment using a ring laser achieved unprecedented accuracy in measuring Earth's axial wobble (nutation and precession), surpassing previous gyroscope and ring laser technologies by a ...

Fomalhaut (Alpha Piscis Austrini), a magnitude 1.2 star, is visible in the southern sky after 8:30 PM local daylight time, reaching its highest point around midnight. Located 25 light-years from Earth ...

While nearly all massive galaxies possess central black holes, the presence of such black holes in dwarf galaxies remains an open question, with previous estimates identifying them in only 0.5% of ...